1. Field
The described technology relates generally to a device for manufacture including a deposition mask.
2. Description of the Related Art
An organic light emitting diode (OLED) display includes two electrodes and an organic emission layer therebetween. Electrons injected from one electrode and holes injected from the other electrode are coupled with each other at the organic emission layer to form excitons, and the excitons emit light while emitting energy.
To form the organic emission layer, an organic material must be deposited on a substrate, and to achieve this, a deposition source filled with the organic material is heated to evaporate the organic material and spray the same over the substrate. In this instance, to deposit the evaporated and sprayed organic material with a specific pattern, an opening is formed corresponding to a specific position to deposit it, and a deposition mask made of a metallic material is used for a remaining position. The deposition mask is classified as a divided mask or a non-divided mask, according to the manufacturing method. The divided mask is used by pulling both ends of a mask sheet that is divided per cell by using a clamper installed at both ends of a manufacturing device to apply a tension force to the mask sheet, and welding it to the mask frame. The non-divided mask, which is a conventional mask, is used by pulling a mother mask that is not divided by using clampers installed at four corners of the manufacturing device to apply the tension force to the mother mask, and welding it to the mask frame.
Particularly, the division method allows good selection, and is easy to repair, so the division method is widely applied to mass production. However, the divided mask combines both ends of the divided mask sheet with the clamper, and applies a tension force thereto, so both ends of the divided mask sheet may be wrinkled. This is because, when a thin-film divided mask sheet is clamped, the thin-film divided mask sheet might not withstand the clamping force of the clamper, so wrinkles may be generated at both the ends of the divided mask. The clamping force may be weakened to stop the generation of wrinkles, but in that case, accurate tension force might not be applied and the clamping may be loose.
Also, when a wrinkle is generated in the length direction of the divided mask sheet, it may be removed by applying the tension force to both ends of the divided mask sheet and clamping the same, and when the wrinkle is already generated in the width direction of the divided mask sheet, the wrinkle might not be removed when the tension force is applied to both ends of the divided mask sheet.
Further, the divided mask sheet may be fixed by vacuum in the stage before it is loaded to a mask frame, and a position of the divided mask sheet may be changed while the clamper clamps the divided mask sheet, so that one or both ends of the divided mask sheet might not be clamped at an accurate position.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the described technology and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.